The charge density of an infinite line of charge is  = 100 nC/m.If zero of potential is chosen to be at a point having a perpendicular distance of 1 m from the line,the electric potential at a perpendicular distance of 50 cm from this line is
A)1.25 kV
B)2.34 kV
C)0
D)-1.25 kV
E)-2.34 kV

Question

Quizplus · Accepted Answer

The electric potential at a point at a perpendicular distance r from an infinite line of charge with charge density λ is given by:

V = (λ/2πε₀) ln(r)

where ε₀ is the permittivity of free space.

Substituting given values, we have:

V = (100x10^-9 / 2πx8.85x10^-12) ln(0.5) = 1.25 kV

Since the potential is positive, zero of potential is at higher potential than the point at a perpendicular distance of 50 cm. Therefore the answer is A.

The Charge Density of an Infinite Line of Charge Is